Facebook is down. Instagram is down. WhatsApp is down. What now?

For brands, like Twitter, the answer was easy: Laugh about a tech rival’s misfortune. For most of the internet, really, the Facebook outage on Monday was a moment to laugh off and log off the world’s largest social network. For millions of advertisers, though, the Facebook hangover was expected to be a tough one. The platform with 10 million advertisers was out for hours, just as the busiest fourth quarter was getting going.

“What happens if this persists,” asked one advertiser, who spoke on the condition of anonymity and works at a big-spending performance marketer that relies on Facebook. “It’s really unfortunate this is starting at the start of Q4.”

The advertisers were starting to see some glimmers of life on Facebook after about six hours of the outage. Shortly after 6 p.m. ET, the social network was flickering back online for many users.

“To the huge community of people and businesses around the world who depend on us: we're sorry,” Facebook said late Monday, as it was getting operational again. “We’ve been working hard to restore access to our apps and services and are happy to report they are coming back online now. Thank you for bearing with us.”

Meanwhile, brands had fun at Facebook’s expense while it lasted, treating it with the giddiness of a snow day only for the internet. Brands and refugees from Instagram and Facebook went to play on Twitter, TikTok and Reddit. “Hello literally everyone,” Twitter posted to its own Twitter account at 1:37 p.m. ET in a nod to all the incoming traffic.

Instagram’s Twitter account joined in, showing it could laugh at itself, tweeting: Hi and happy Monday (spiral eyes dizzy emoji.)

“U ok bestie,” Burger King tweeted in response to Instagram.

Twitter’s tweet sparked 2.5 million likes and almost 500,000 retweets by the end of the day.

It was unclear what caused the Facebook outage, but by internet standards it was a large one. Facebook and all its apps, including Instagram and WhatsApp, were thrown off line by what appeared to be a Domain Name System malfunction, and no one could access Facebook apps or websites starting at noon ET.

The outage even affected Facebook’s internal corporate communications, according to advertisers, who said they were receiving emails from Facebook reps using their personal email address.

“We’re aware that some people are having trouble accessing our apps and products,” Andy Stone, Facebook’s communications director, tweeted just after noon ET. “We’re working to get things back to normal as quickly as possible, and we apologize for any inconvenience.”

Most major platforms suffer some period of downtime, and Facebook has had its share of outages, like one that flung people off the social network for hours in 2019.

When Facebook goes down, it’s not just the 2.8 billion daily users across its apps that can’t access the platform. There are millions of advertisers running campaigns on Facebook Ads Manager that run into trouble making their ad spending goals. Facebook made almost $85 billion in ad revenue in 2020, which amounts to about $233 million a day flowing through its system.

Outages cause problems for small businesses and large brands trying to make sales, especially as the holiday advertising season is just getting started.

Facebook was having a bad day already after a “whistleblower” came froward in a primetime exposé on “60 Minutes” on Sunday night. The “whistleblower” Frances Haugen was set to testify before the Senate on Tuesday about her contention that Facebook harms the general public, which she claimed she uncovered in thousands of documents detailing the company’s internal deliberations.

What Facebook is telling advertisers about the whistleblower

On Monday, there were concerns that the Facebook outage could be a sophisticated attack against the company, or perhaps from subversive elements within the company. Facebook declined to comment on how it would fix the issue, or the cause.

Most people and advertisers took the outage in stride though, expecting Facebook, Instagram and WhatsApp would return. “I imagine they're pulling every possible lever right now to get everything online,” said a Facebook advertiser, who spoke on condition of anonymity.

Mike Schroepfer, Facebook's chief technology officer, tweeted at 3:52 p.m. ET: “Sincere apologies to everyone impacted by outages of Facebook powered services right now. We are experiencing networking issues and teams are working as fast as possible to debug and restore as fast as possible."

What Facebook is telling advertisers about the whistleblower

In the meantime, brands were still having a bit of fun while it lasted. Even the Empire State Building had something to say about it.